Apparatus for charging and discharging concrete mixers



2 Sheets-Sheet 1 i Samuel Shaferllt INVENTOR S. SHAFER, JR

APPARATUS FOR CHARGING AND I DISGHARGING CONGRETE MIXERS Filed Jan, 4, 1941 June 9, 1942.

f ATTORNEY.

June 9, 1942. s SHAFER, JR

APPARATUS FOR CHARGING AND DISCHARGING CONCRETE MIXERS 2 sheets-Sheet 2 FIG. 2.

Filed Jail. 4, 1941 SamueZ Shagerir: INVENT R.

ATTORNEY.

Patented June 9, I942 "UNITED STATES PPARATUS FOR. CHARGING Aim ins- CHARGING concna'm MIXERS Samuel'Shafer, Jr., Milwaukee,,wis,, as signor to Chain Belt "Company, Milwaukee, Wis., a cornotation of Wisconsin Application January}, 1941, Serial No. 373,066

-. 6 Claims. c l'. 259-1s1) The present invention relates in general to "concrete mixing apparatus of the. rotative drum type providing a simple means for ingress of concrete aggregate and egress of mixed concrete;

and more particularly the invention relates'to 5 improvedcharge and discharge means for that type of concrete mixers commonly known as truck mixers, which have a suitably powered rotative mixing or agitating .drum mounted longitudinally on a motor truck for rapidly transport- -ing concreteconsiderable distances. With this.

invention the charging and discharging of such mixers I is greatly improved and facilitated through a'single drum opening. 7

A primary object, among others, of the present invention is .to provide a,novel restraining ele-- ment in'association with the common charge and dischargeppening of a mixing drum whereby a drum closing door and the attendant controlling or actuating mechanism arerendered unnecessary.

l A further object is'to provide a combined charge and discharge element in association with the single opening of a mixing drum whereby through novel means, the elements may. be positioned to charge the drum' with concrete'aggregate and at the proper time may be positioned for discharge of concrete from the-drum.

A still further object is to provide a novel ref ceptacle to accommodate concrete surging Zing device hereinafter described. Flange I8 is through the drum opening of a concrete mixer.

where the latter is provided with means for forcingconcrete out of said opening during rotation;

Another object of the present invention is to provide a rotative element for loading and also unloadinga rotating mixer drum, whichelement is resiliently held in frictional engagement with the drum adjacent its opening, whereby the-element may be held stationary or rotated at will to loading or unloading position through and by '40 means of drum revolution. I

' A still further object is to provide an improved charging and discharging apparatus which will. be simple and inexpensive to manufacture, and

which. willperform efllciently in the environment heretofore described and with -a minimum amount of trouble during its periodof use.

Other objects and advantageous features of the present invention willbe appreciated by those skilled in the art from reading the following description and by reference to the accompanying drawings, in which:

Figure l is a central longitudinal section of the device with the charging element in upright position;

- Figure 2 is-s'ection taken on the line 2-2 of Figure 1;

Figures 3 and 4 are enlarged radial sections through the journal for the hopper, showing'the' method of mounting the bearing plates, and

forming the seal;

Figure 5 is an enlarged radial section of the I, sealing ring before assembly; and

Figure 6 is a section 'taken on the line 8-6 of Figure 2. a i

In the drawings, the mixing drum I2 is illustrated as mounted on motor truck l3 and is op- -eratively rotatable on an axisinclined to the horizontal, its rearward portion elevated to provide a high point of charge or discharge for the drums contents. The drum is mounted for re.-

- tation on a suitable frame I, and in a conventional manner, the forward portion being supported on a bearingarranged axially of the drum (not shown) while the rear portion is supported on a pair of'rollers l5 which cooperate with a cylindrical flange l6 mounted exteriorly of the shown as rivetedto the end of the drum, but it could be welded or'otherwise secured, or it might form an integralpart of the frusto-conical discharge portion of the drum. This ring is sufficiently thick to present an appreciable surface l9 transverse or radially to. the drum axis at the rear of the drum for mounting of the bearing assembly, and to accomplish this, a number of angularly spaced holes are tapped into this surface to accommodate threaded pegs 20 disposed for support of one ofthe bearing plates. (See Fig. 4.)

Mounted on the outer cylindrical surface of ring II is a charging and discharging element, generally designated 2|, which is angularly shaped, and when in upright position for charging the drum serves as a hopper and has a sloping rear wall 22. This hopper is secured to member 23, which is L shaped in cross section with a cylindrical portion journaled on ring IS, the other portion being disposed radially of the drum axis, space being provided between the end of the drum and the member to accommodate a pair of readily, replaceable bearing plates 24 and 25.

Plate 24 is provided with radially spaced apertures for the pegs 20, which are threaded into the end of the drum, and thereby prevent relative rotation between thedrum and the plate .24. A similar construction keys the correspondingly shaped and mating plate "to the hopper, radially spaced pegs 26 in this instance, being 'threaded into the member 23, and being" contained in apertures correspondingly spaced in 4 the bearing plate 25.

Disposed between the plate 24 and theendof the drum and within the confines of the two bearing plates is-a sealing member 21, of rubber or other suitable material, the inner surface of 3 which forms a substantially smooth continuation of the inside of the drum. In Figure 5 is shown a cross section of this seal before compressing to the contour indicatedin Figure 4. Lip 21' is extended outwardly to insure resilient liquid tight contact'with the radial-face 23 of the hopper 20 plate when the sameis assembled on the mixer 'drum as shown in Figures 3 and 4. Lubricant may be admitted to the space between the bearings through a grease fitting 28 threaded into the member 23 and through apertures 29 ex tending. through plate 25. Lubricant may be forced under the sealing member by means of In order to keep the bearing plates in contact and to prevent the hopper from becoming disengaged from the mixer, a. hub 33 is mounted axially in the ,drum near the end opening and a rod 3 3 is supported thereby and arranged axially of said opening. Rod 36 extends through portion of flange 23 which serves as a brake drum The band is retained in a groove 43 in this drum, which groove is wider thanthe band in order to permit axial movement in accordance with the yieldable pressure exerted .by spring 31. To prevent the band from draggingon the drum when the brake is disengaged, and to support, the band;

a a bracket 44, secured to the band, is pinned to one of the upright members 45 on the mixer 0 frame, preferably the member on the right hand side when the machine is viewed from the rear as in Figure 2. The band is split and the ends areprovided with ears 46 which are threaded I with right and left hand threads respectively for 15 engagement with a correspondingly threaded rod 61, said rodbeing coupled to an actuatingrod 48 journaledin a bracket 49, mounted on upright member 50 of the mixer frame. Axial movement of the rod in bracket-49 is prevented by coupling El and by collars 52 disposed at either side of the upper bearing 53 of the bracket and the rod is set at an angle to the horizontal in order that the position for manual operation.

To insure accurate positioning of' the charge and discharge device, one ofthe rims on the member 23 which define the groove for the brake band, preferably the forward rim 55, is notched I as 56 and 51. These notches, (somewhat V shaped), which are 180 apart, are located so that.

' when the chargingdevice is in either charging 'position' or in discharging position, one of the notches'will be disposed for engagement with a spring actuated detent 58 mounted on bracket 59 5 supported by upright member 50. The spring detent is joumaled in the bracket and is normally kept in engagement wi the rim by means 'of a compression spring 60 disposed on the shaft of the. detent between the bracket and a suitably the rear wall 22 of the hopper, a cylindrical casformed shoulder on the shaft. To insure proper ing 35 secured to the hopper journaling the rod.. Mounted in this casing and surrounding rodtt is spring 8? which is pressed against the end of the casing by nuts 38 threaded to rod 3%. A

cap 36 housing spring 31 and slidably fitting over the end of casing 35 is interposed between the spring and nuts 38. In this manner the hopper due to the arrangement shown. Since the hopper is not supported on the rod 36, the rod need not be of large diameter, with the result that very little obstruction is afiorded to the passage of material through the hopper. Suitable packing 'material 39 is disposed between rod 3t and casing 35 to prevent material getting into'the journal.

With the hopper in the positions shown in Figure 1, material may be readily charged into the drum and the drum may be rotated during charging, the internal drum blades til moving 6 materialitoward the forward end of the drum to accommodate the charged material. With this arrangement it is possible to provide the bottom of the hopper (as shown in Figures 1 and 3) with engagement of the detent 58 with the notches,

the forward portion of the detent is squared and provided with a square bearing 6!. For ease in operation, a handle 62 is provided. at the end of the detent on the outer side of the bracket from spring 60. A

It will be understood that the interior of the drum may be provided with spirally arranged blades ill designed to move material in either 59 forward or rearward axial direction depending on the direction of rotation of the drum. During charging operations, the hopper is in upright position as shown in Figure 1, the brake is locked and the detent is in the appropriate notch.

: Material is charged into the hopper from above and slides into the drum, where-the aforesaid blades move it forward thus providing space for additional material.

After the concrete is mixed. the brake is re- 0 leasedby rotation of hand wheel 5G in the suitable direction and the detent is pulled from the notch in which it was contained. Under frictional engagement between the bearing plates 2% and 25, and due to pressure from spring 31,

5 the hopper will rotate with the drum until the notch 51 is in line with the detent, at which time the pressure from spring will snap the detent into the notch and accurately position the hopper, after 180 of rotation to the dotted line a lip-portion M which'exte ds o e the seal and. position shown in Figure -l,'for discharge. The

thereby tends to chute material into, the drum rather than drop it directly on the seal.

To maintain the hopper in upright position during charging, a brake is provided comprising a brake band 62 extending around the cylindrical brake may also be us ed.'to control and retard the rotation of the hopper, whereby the force applied against the detent as it snaps into its notch may be relieved.

During dischargathe direction of drum rotahand wheel 54 may be located in a, convenient tion isopposite to that during charging, and

blades 40 move concrete rearwardly through the opening and into the down-tumed hopper from which it is chuted into receptacles or forms. After the drum is discharged, the hopper may be rotated into up-right position through its contact with the drum, provided the detent and brake are released, and the drum may then receive anpressure and in sealed relationship with the end of the drum, the bearing plates being protected from material by the presence of the overlapping seal. The device may be easily removed from the drum by release of the brake and locking assembly and removal of the nuts 38 which hold it in contact with the drum. Conversely the amount of pressure may be increased by tightening of the nuts to compress spring 31, and also thereby taking up the wear between the bearing surfaces which may occur. 1

It will be understood that various equivalents may be utilized in accomplishing the objects and functions of the invention. For instance, instead of flat bearing surfaces as are provided for by plates 24 and 25, anti-friction bearing elements may be employed. Accordingly, the invention is not to be limited to the details of construction as shown herein. the present construction, because of its simplicity, being merely a preferred embodiment of the invention.

I claim:

1. In a concrete mixer, the combination of a rotatable drum having an axial opening at one end, an annular portion external to and adjacent said openin a charging element mounted on the annular portion ofsaid drum and supported entirely by said drum, and means mounted axially of said drum yieldably urging saidcharging element against said drum.

2. In a transit concrete mixer, the combination of a rotatable drum having an axial opening at one end, an annular portion external to and adjacent said opening, a charging hopper supported solely by said annular portion, a bar arranged axially of said drum and extendin through said hopper and resilient means mounted on said bar yieldably urging said charging hopper into sealing contact with the end of said drum.

3. In a concrete mixer, the combination of a rotatable drum having an axial opening at one end, a charging and discharging device supported solely by said drum but free to move rotatively Y and axially thereof,-means mounted axially of said drum yieldably urging .said device against said drum, means for maintaining said device in one of a plurality of fixed radial positions and means for relieving said last named means whereby said device may rotate under frictional engagement with said drum.

4. In a concrete mixer, the combination of a rotatable drum having an axial opening at one end, a frame -upon which said drum is mounted, an angularly shaped feeding device supported solely by said drum and cooperating with saidopening, resilient means mounted axially of said drum constantly urging said device into sealing contact with the perimeter of said drum opening, means mounted on said frame for maintaining said device in one position for charging and in another position for discharging and means for releasing said last named means, whereby said device may rotate from one position to the other through frictional engagement with said rotatable drum.

5. In a concrete mixer, the combination of a rotatable drum having an axial opening at one end, a charging and discharging device mounted on said drum for cooperation with said opening,

said device being movable axially and rotatively with respect to said drum, means yieldably urging said device in position against said drum. means holding said device for either charging or discharging, means for retardingrotation of said device, and means for controlling the retarding effect of said last named means.

6. In a transit concrete mixer, the combination of a mixing drum which is rotatable about a fixed-inclined. axis and has an axially disposed opening at its higher end, said drum having a flange surrounding said opening affording a radially disposed face, a charging device mounted on said flange and supported solely by said drum, said device also having a face radiallydisposed with respect to the drum axis, a replaceable bearing member disposed between said faces, flexible means sealing said bearing member against ma-, terial passing through said opening, pressural means urging said charging device axially toward said drum, whereby said bearing may be engaged and said seal may be closed, and means holding said device in hopper charging position during rotation of said drum.

A SAMUEL SHAFER, JR.

. I cERTIFIcATfEOFcomcTIoN. e Patent No. 2,285,685. I June 9, 191m. I SAMUEL SHAFER, JR.

It is herebiv certified that error appeers in the printed specification of the above numbered patent reqliipihg corre'ctionae follows: Pege 3, 86F

(and column, lihe 33, claim 5, before "against" strike out "iriposition" and ineent the same before "for either" in line 314., some claim; and thet the said I-.ettere' Patent should bereeld with this correction therein that the same may conform to the record of the ease in the. Patent Office. Signed and s ealedthLe'hth day ofAugus t, A. D. 19!;2;

Heizry Arsdale, v (See1') Acting dommie sioner'of Petents, 

